Who are these people who are getting so many long e-mails that they need them all summarized?
I get a _lot_ of email, I think, compared to most people I know, and I cannot for the life of me say that this is a thing I've ever wanted. I either want to read the e-mail in its entirety or I do not want to read it at all, having a shorter and less accurate version is not helpful to me at all.
Long email threads resent to you where the only relevant email is the last one. Execs who receive thousands of emails looking for job or offering services.
I'm in the same boat as you; but I really don't receive so much email really.